>>> On 26.06.18 at 09:18, wrote: > The STI instances were moved (or added in the INT80 case) to meet TLB > flush requirements. When XPTI is disabled, they can be put back where > they were (or omitted in the INT80 case). > > Signed-off-by: Jan Beulich <jbeul...@suse.com> > Tested-by: Juergen Gross <jgr...@suse.com> > Reviewed-by: Juergen Gross <jgr...@suse.com> > Reviewed-by: Wei Liu <wei.l...@citrix.com>
I'd not be overly concerned if this was nack-ed for an acceptable reason, but I'd like to hear so in that case, because the alternative to this patch is to drop the synthetic NO_XPTI feature flag, which is not used anywhere else without this change. Jan > --- > v5: Re-base. > v4: Split off from earlier patch. > > --- a/xen/arch/x86/x86_64/compat/entry.S > +++ b/xen/arch/x86/x86_64/compat/entry.S > @@ -200,7 +200,7 @@ ENTRY(cr4_pv32_restore) > > /* See lstar_enter for entry register state. */ > ENTRY(cstar_enter) > - /* sti could live here when we don't switch page tables below. */ > + ALTERNATIVE nop, sti, X86_FEATURE_NO_XPTI > CR4_PV32_RESTORE > movq 8(%rsp),%rax /* Restore %rax. */ > movq $FLAT_USER_SS32, 8(%rsp) /* Assume a 64bit domain. Compat > handled lower. */ > @@ -223,7 +223,7 @@ ENTRY(cstar_enter) > /* %r12 is still zero at this point. */ > mov %r12, STACK_CPUINFO_FIELD(xen_cr3)(%rbx) > .Lcstar_cr3_okay: > - sti > + ALTERNATIVE sti, "", X86_FEATURE_NO_XPTI > > movq STACK_CPUINFO_FIELD(current_vcpu)(%rbx), %rbx > movq VCPU_domain(%rbx),%rcx > --- a/xen/arch/x86/x86_64/entry.S > +++ b/xen/arch/x86/x86_64/entry.S > @@ -247,7 +247,7 @@ UNLIKELY_END(exit_cr3) > * %ss must be saved into the space left by the trampoline. > */ > ENTRY(lstar_enter) > - /* sti could live here when we don't switch page tables below. */ > + ALTERNATIVE nop, sti, X86_FEATURE_NO_XPTI > movq 8(%rsp),%rax /* Restore %rax. */ > movq $FLAT_KERNEL_SS,8(%rsp) > pushq %r11 > @@ -269,7 +269,7 @@ ENTRY(lstar_enter) > /* %r12 is still zero at this point. */ > mov %r12, STACK_CPUINFO_FIELD(xen_cr3)(%rbx) > .Llstar_cr3_okay: > - sti > + ALTERNATIVE sti, "", X86_FEATURE_NO_XPTI > > movq STACK_CPUINFO_FIELD(current_vcpu)(%rbx), %rbx > testb $TF_kernel_mode,VCPU_thread_flags(%rbx) > @@ -280,7 +280,7 @@ ENTRY(lstar_enter) > jmp test_all_events > > ENTRY(sysenter_entry) > - /* sti could live here when we don't switch page tables below. */ > + ALTERNATIVE nop, sti, X86_FEATURE_NO_XPTI > pushq $FLAT_USER_SS > pushq $0 > pushfq > @@ -306,7 +306,7 @@ GLOBAL(sysenter_eflags_saved) > /* %r12 is still zero at this point. */ > mov %r12, STACK_CPUINFO_FIELD(xen_cr3)(%rbx) > .Lsyse_cr3_okay: > - sti > + ALTERNATIVE sti, "", X86_FEATURE_NO_XPTI > > movq STACK_CPUINFO_FIELD(current_vcpu)(%rbx), %rbx > cmpb $0,VCPU_sysenter_disables_events(%rbx) > @@ -356,7 +356,7 @@ ENTRY(int80_direct_trap) > /* %r12 is still zero at this point. */ > mov %r12, STACK_CPUINFO_FIELD(xen_cr3)(%rbx) > .Lint80_cr3_okay: > - sti > + ALTERNATIVE sti, "", X86_FEATURE_NO_XPTI > > cmpb $0,untrusted_msi(%rip) > UNLIKELY_START(ne, msi_check) > > > > _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
